Jute-based porous biomass carbon composited by Fe3O4 nanoparticles as an excellent microwave absorber

Porous jute biomass carbon (PJBC) composited by Fe3O4 nanoparticles were successfully prepared by a chemical coprecipitation method at a low temperature of 60 degrees C, which is very simple to prepare a high degree of purity of Fe3O4 nanoparticles. The structure, morphology, and microwave absorption performances of the Fe3O4/PJBC composites were investigated in detail. Due to the porous structure and large interfaces between Fe3O4 and PJBC, the Fe3O4/PJBC composites show excellent microwave absorption performances. The minimum reflection loss (RL) value of -39.5 dB is obtained for the Fe3O4/PJBC composites at the frequency of 6.4 GHz. When the thickness is only 1.6 mm, an effective absorption bandwidth (RL <= -10 dB) for 5 GHz is achieved from 13.8 to 17.8 GHz. The excellent microwave absorption performances for the Fe3O4/PJBC composites are rooted in enhanced impedance matching, large interfaces, ionic polarization, eddy loss, natural resonance, and multiple reflection and scattering. Consequently, considering market applications and the cost, the Fe3O4/PJBC composite in this work can be a promising candidate for microwave absorber. (C) 2019 Elsevier B.V. All rights reserved.